I did think that but was hesitant to mention it for fear of being shot down. :wink:
It occurs to me that I have a 1/2" chuck somewhere that may have the base drilled out*. You could then possibly put bits in backwards but I'm not sure how well that would work although I'm sure I've done something similar before to line something up in the metalwork lathe. Fixing the chuck could be a problem though.
* It was a method advocated to remove a stuck arbor from a chuck - drill the back out with say a 3/8" bit and punch off the arbor with a drift. I got a very nice Jacobs chuck that way as the previous owner could'nt get the arbor out!